Film bladder, actuator and vehicle seat

The film bubble (1) has upper and lower film walls (OF,UF), where a longitudinal weld is formed. One or more longitudinal weld seams (5a) of the film bubble are provided in a slide area (FB) between two longitudinal side edges (13) of the film bubble. The film bubble forms an elongated, tube-like structure in an inflated fitted condition. The film bubble consists of single plastic film (2a) or two plastic films. An independent claim is also included for a vehicle seat with two seat structures.